As conventional semiconductor devices, a semiconductor device is known in which a semiconductor chip and a base plate are sealed by a sealing resin. A method is studied for manufacturing a plurality of semiconductor devices easily at low cost by collectively forming a plurality of these semiconductor devices. This method will be described in detail below.
First, the lower surfaces of a plurality of semiconductor chips are pasted on a tool. Next, a sealing resin is formed on the tool including all of a plurality of semiconductor chips. By this means, individual semiconductor chips are sealed by the sealing resin. Next, the sealing resin is removed such that the upper surface of each semiconductor chip is exposed, and one base plate is pasted on the sealing resin including the upper surfaces of a plurality of semiconductor chips. Then, the tool is peeled off from the assembly of a plurality of semiconductor chips which is integrated by the sealing resin and base plates, and wiring patterns, solder resist film and BGA balls are collectively formed in the lower surface of each semiconductor chip. Finally, the sealing resin and base plates are cut by a method such as dicing, to individually divide semiconductor devices.
In addition, with this description, collective formation of a plurality of the above semiconductor devices means collectively sealing a plurality of semiconductor chips by means of a resin, collectively forming, for example, wiring patterns and then cutting the resin to form a plurality of semiconductor devices.
However, with the above method of collectively forming a plurality of conventional semiconductor devices, particularly when base plates made of a material harder than a resin such as a metal or ceramic, are applied, it is difficult to cut the base plates in the final shaving and cutting step. Therefore, there is a problem that the shaving and cutting step causes damages such as cutting burrs in wiring patterns and solder resist film, thereby decreasing the yield of devices.